High tensile hot-rolled steel sheet excellent in resistance to scuff on mold and in fatigue characteristics

A high-strength hot-rolled steel sheet having excellent anti-die-galling property and anti-fatigue property, comprising C:

• not less than 0.02 mass % but not more than 0.2 mass %, Si:
• not less than 0.2 mass % but not more than 1.2 mass %, Mn:
• not less than 1.0 mass % but not more than 3.0 mass %, Mo:
• not less than 0.1 mass % but not more than 1.0 mass %, Al:
• not less than 0.01 mass % but not more than 0.1 mass %, P:
• not more than 0.03 mass % and S:
• not more than 0.01 mass %, and further containing at least one selected from Cr:
• not more than 0.3 mass %, Ca:
• not less than 0.001 mass % but not more than 0.005 mass % and REM:
• not less than 0.001 mass % but not more than 0.005 mass % and the remainder being substantially Fe and inevitable impurities, and has a tensile strength of not less than 590 MPa, a yield ratio of less than 70%, a steel microstructure containing not less than 55 vol % of ferrite and not less than 10 vol % but not more than 40 vol % of martensite provided that a total of both is not less than 95 vol %, and a ratio ds/dc of an average crystal grain size ds of the ferrite in a region ranging from a surface of the steel sheet to a position corresponding to a quarter-thickness in the steel sheet to an average crystal grain size dc of the ferrite in a region ranging from the position corresponding to the quarter-thickness in the steel sheet to a center of a thickness in the steel sheet is 0.3<ds/dc≦1.0, and a surface roughness is not more than 1.5 μm as an arithmetic mean roughness Ra.